Character and Distribution of Geometrically Necessary Dislocations in Polycrystalline Tantalum.

Autor:	Hansen LT; Department of Mechanical Engineering, Brigham Young University, EB 350, Provo, UT 84602, USA., Carroll JD; Materials Science and Engineering Center, Sandia National Laboratories, 1515 Eubank SE, Albuquerque, NM 87123, USA., Homer ER; Department of Mechanical Engineering, Brigham Young University, EB 350, Provo, UT 84602, USA., Wagoner RH; Department of Materials Science and Engineering, Ohio State University, 2041 College Rd., Columbus, OH 43210, USA., Zhou G; Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China., Fullwood DT; Department of Mechanical Engineering, Brigham Young University, EB 350, Provo, UT 84602, USA.
Jazyk:	angličtina
Zdroj:	Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada [Microsc Microanal] 2023 Jun 09; Vol. 29 (3), pp. 953-966.
DOI:	10.1093/micmic/ozad049
Abstrakt:	Geometrically necessary dislocations (GNDs) play a key role in accommodating strain incompatibility between neighboring grains in polycrystalline materials. One critical step toward accurately capturing GNDs in deformation models involves studying the microstructural features that promote GND accumulation and the resulting character of GND fields. This study utilizes high-resolution electron backscatter diffraction to map GND populations in a large polycrystalline sample of pure tantalum, under simple tension. A total of 1,989 grains, 3,518 grain boundaries (GBs), and 3,207 triple junctions (TJs) were examined in a subsurface region of the sample. Correlations between GND density and GB character, and to some extent, TJ character, are investigated. Statistical geometrical relationships between these entities are quantified, and also visualized, using a novel application of two-point statistics. The nature of GNDs across the sample is also visualized and assessed using a recently developed method of mapping the local net Burgers vectors. The different approaches to characterizing GND distribution are compared in terms of how they quantify the size of near boundary gradient zones. Competing Interests: Conflict of Interest The author(s) declare that they have no competing interest. (© The Author(s) 2023. Published by Oxford University Press on behalf of the Microscopy Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
Databáze:	MEDLINE
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